1. Field of Invention
The invention relates to a light emitting diode (LED) module as the light source of an electronic device, including an epitaxy chip, an electrode, and a substrate with good insulation and good heat dissipation. More particularly, the invention relates to an LED module having a plurality of epitaxy chips on a single substrate after the epitaxy chips have been cut, the eptiaxy chip having good heat dissipation, high brightness and full-area illumination.
2. Related Art
The development of LED technology began in 1970. For decades, people have looked for an effective means of illumination. However, various factors such as brightness and durability of the illumination products have limited their success in commercialization. With LED technology, some of these problems have been successfully solved, and LEDs are now widely used in illumination devices. Compared to traditional light sources, the LED has advantages such as small size, good illumination efficiency, long service life, high response speed, high reliability, and good wear resistance. LEDs allow the production of small, flexible or array-shaped devices, without heat radiation or pollution by toxic substances such as silver.
Nowadays, LED technology has become mature, and has found a wide range of applications such as in vehicle dashboards, as the backlight source of liquid crystal display devices, as interior illumination, and as the light source of scanners or fax machines, etc. However, technical developments are needed to manufacture a LED that has low power consumption, high efficiency and high brightness.
Many LED structures have been proposed in the past but most of which focus on illumination properties. The prior art particularly emphasizes technical improvement with respect to illumination efficiency and brightness, by optimally arranging the LEDs according to rectangular or circular distributions so as to increase the illumination area. LED assembly according to these distribution schemes is problematic because the LEDs are separately formed on a substrate. LED rearrangement according to a desired distribution is time-consuming and complicates the manual and mechanical assembly process. When an illumination device uses LEDs as its light source, the heat generated from the operation of the LEDs is also a concern.
Tolerance to power consumption also plays an important role in LED illumination performance. If the LED can tolerate high power consumption, its brightness increases. Thermal factors also constitute an important characteristic of the LED. Heat dissipation can be achieved via various packaging structures. The heat irradiated from the LED in operation is dissipated via an external means such as an airtight mask provided with a liquid or gas filled therein, so that the LED can tolerate high power consumption without property alterations. Although such external means achieves heat dissipation, it adds a processing step to the manufacturing process. Furthermore, the external heat dissipation means may increase the burden for product quality testing.